Effects of growing media and rhizobacteria used in organic seedling production on seedling growth and greenhouse plant growing

This study was conducted in the years of 2014-2015 and it was aimed to determine the effects of different Plant Growth-Promoting Rhizobacteria (PGPR) on organic seedling production grown in different growing media. In the experiments as plant material tomato (cv. Melis), watermelon (cv. Asbal) and head lettuce (cv. Papiro) species which have a high commercial importance were selected. Those species were grown in 4 growing media [Imported peat (P), local peat + clinoptilolite + vermicompost (LP+CLI+VC), local peat + perlite + vermicompost (LP+PER+VC) and 60% local peat+40% vermicompost (60%LP+40%VC)] and 11 different bacteria (1: Psedomonas punonensis 37, 2: Pseudomonas fluorescens 30, 3: Ochrobactrum pseudintermedium 80, 4: Pantoea agglomerans 83, 5: Bacillus subtilis 66/3, 6: Bacillus thuringiensis 99, 7: Pseudomonas putida18/1K 8: Pseudomonas fluorescens 112, 9: Pseudomonas fluorescens S5/4, 10: Pseudomonas fluorescens TR21/1,11: Psedomonas punonensis 56) were tested. Seeds inoculated with bacteria were sown on 4 different organic media. Seedling production was done twice and the best growing medium (60%LP +40%VC) and four PGPR ((5-7-8-11 ve 5+8) were determined according to the seedling quality parameters. Selected bacteria were tested at the seedling stage and in plant production in 3 crop species in order to determine the effects on yield and quality parameters during the fall and spring seasons. Although there was no significant difference in terms of yield in watermelon and head lettuce, Bacillus subtilis 66/3 was found promising. In tomato production no yield was obtained in fall due to the downy mildew and in the second experiment the highest yield was obtained from B5+8 combination. However among the treatments no significant difference was found in yield of spring season production. A better performance was observed with Pseudomonas fluorescens 112 when the other parameters were evaluated.